Electrical connector having coaxial barrels of different diameters



y 1952 v. E. CARLSON 2,596,528

, ELECTRICAL CONNECTOR HAVING COAXIAL BARRELS OF DIFFERENT DIAMETERS Filed on. 25, 1949 12 liill'lff'l Ypvv-JIIIIIIIIIII b Ill-II M x INVENTOR fi m am t? CwPua/v.

ATTOR N EYS ELECTRICAL ooNNEo ioniiIivIn coaxin BARRELSOF'DIFFEREN nmMETnB-S Vernon E. 'CarlsomCamp :Hill, Pa -iassignonto' Aircraft-Marine Products Inc"; H

Continuation of applicatio W July 6, 1945. Thisapplica on'flcto Serial No. 123,479

. 'Ihis invention: relates More particularly it pertains to a connector and a method of manufacturing a connector having two. substantially ,coaxially arranged barrels forming .a composite ferrule for receiving'and embracing boththe stripped end of the wire of an electrical conductor'and the endof theinsulation sheath ico'vering the conductor. H The present application is a continuation of my application Serial No. 603,532, filed July 6, 1945, now abandoned, which itself is a continuation in part of my applications Serial No. 455,034,.filed August 17, 1942, Patent Number 2,385,792, issued October 2,1945, and Serial No; 530,336, filed April 10, 1944, Crimp type or solderless connectors are'wellknown. Amongthe kinds in common use is one whereby the stripped end of a wire is permanently fastened within the ferrule of the connector and the end ofthe insulation sheath covering the wire is supported by a sleeve, or cars, or some other insulation receiving portion of the connector. One such connector is disclosed and claimed in the application of Stephen N. Buchanan, Serial No. 421,408, Patent Number 2,379,567, issued July 3, 1945; another is disclosed and claimed in the application of James 0. Johnson, Serial No. 530,313, Patent Number 2,452,932, issued November 2, 1948. Each of these connectors has supplied a long felt want and has enjoyed commercial success and each has its own advantages. The seamless sleeve of the Buchanan connector which was telescoped over the wire-receiving ferrule substantially strengthened the ferrule against opening during crimping and at the same timeprovided an excellent supporting collar for the endof the insulation sheath. The connector was subject .to improvement to the extent that it was a relatively expensive item to produce. Various unsuccessful attempts have been made to provide a connector having the same functional advantages which could be manufactured more inexpensively. The Johns-on connector has enjoyed considerable commercial success and has been widely used. Its insulation support does not give the same degree of protection against moisture as the insulation support of the Buchanan connector. On the other hand it is integral with the wire-gripping ferrule of the connector and hence eliminates the need of Buchanans separate seamless sleeve and of various assembly operations. The art has long recognized that alconnector made in one piece wholly by a series of mechanically, performed operations which would support the "insulation sheath,.' repel mois-l ture, and make apr-o'per, permanent crimp'on the wire would have advantages over some of the to electrical connectors.

arrisburg; Pa.s-

best connectors of theprior' art; By the resent invention such a connector hasbeen produced andat 'th'e Esameaztime with an' 'important saving of the high quality; sheet=stock from which electricaliiconnectorsiare iabricated. 3:: i fiwIt'iis an- 'objectuofirthe :present invention to provide a connector and a method ofthe: characterydes'cribed having-to a notable extent the characteristics #and' advantages hereinbefore set forth-.-;- Another objectdsthe provision of a onepiece electrical-connectorsuitable for crimping onto the wire and for receiving and supporting the end-of :the insulation sheath of an electrical conductor. "Stillanother object resides inmaking a connector having a smooth, funnel-like ferrule opening for directingthe endof a wire into the connector ferrulewA further'object is to provide a method of manufacture whereby electrical connectors ofthe'sought-after type mentioned may be economically produced. Other objects will -be -in partpointed out as the description proceeds and will in part become apparent therefrom. j i

According-to the present invention an electrical connector is made from a strip of metal, preferably pure electrical copper, the strip enterms one end -of--the process and the finished article leaving-at the other end. A rectangular transverse porticn-ofthe stripmay be considered as theblank and it may be severed at this stage or advantageously ata later stage in the format iono f the: terminal,- oreven after the terminal is completely iormed andlapplied to the .wire alter; the -manner-described and claimed in the copending application of William-S. Watts, Serial No.- 514,2 4, filed December; 14, d943, now, aban+ cloned; Ayportiontotithe iblank is spread by a swagi-ngnoperatiori tea-greater width than the Width-,of rthe, original blank.- The blank is trimmedto-give-a ferrule-forming portion which is thereafter gradually shaped by a seriesof steps into-.two integral coaxial-barrels. One barrel is 'formeddrom theswaged portion. and is ofsomewhat-greaterg diameter ,than}-the other barrel. ci mi re ee i ner ate ?l fl.;:- s l full width, of the I i M n the. .connector was formedl -.In the" preferred embodiment' the circumference of..the swagedbarrel is greater than t9 nail sulation sheath. Some of the advantages which result from such barbs are brought out in the copending application of Vernon E. Carlson and Thomas C. Freedom, Serial No. 459,624, filed September 25, 1942, Patent Number 2,405,111, issued August 6, 1946.

From the foregoing it will be seen that an electrical connector made in accordanc with the present invention is well adapted to attain the ends and objects hereinbefore set forth and to be economically manufactured since both the article and the method of making it are suited to common production methods and are susceptible to a wide latitud of variations as may be desirable in adapting the invention to different applications.

I claim:

1. In the art of manufacturing electrical connectors, that improvement which includes the steps of preparing an elongated blank of sheet material, substantially uniformly swaging a strip across one end of the blank to a thickness of about two-thirds the thickness of the unswaged blank, trimming the blank to define a terminal contact portion and a ferrule forming portion, the swaged strip being located across the end of the ferrule forming portion, trimming the transverse end edge of the swaged strip along an arc of radius about three to five times the diameter of the ferrule to be formed therefrom, the center of the are lying in the long axis of the blank, bending the ferrule forming portion along the longitudinal axis of the blank to a troughlike configuration of U-shaped cross-section, offsetting the swaged strip from the rest of the ferrule forming portion first only at the central base portion of the U and thereafter up both sides of the U to give a U-shaped cross-section through the swaged strip which is similar to but larger than the original U-shaped cross section, and finally closing and longitudinally deforming the U-shaped ferrule forming portion to give two cylindrically shaped, integral barrel-like portions coaxially arranged but the one formed from the swaged portion being of greater diameter than the other and having its receiving edge lying in a plane normal to its long axis.

2. The method of manufacturing a ferrule having coaxial portions of differing internal diameter that comprises cutting an elongated sheet metal blank having width at one edge substantially equal to the internal circumference of one portion of the ferrule to be produced and having a width at the other edge substantially less than the internal circumference of the portion of the ferrule to be produced therefrom, swaging said other edge of said blank to reduce its thickness and to increase the width of material at that edge of the blank, trimming said other edge of 19 said blank along an arc of radius of three to five times the internal diameter of the ferrule portion to be produced therefrom, the center of said are lying on the long axis of the lank, trimming the unswaged portion of the blank to leave a flat terminal contact portion, deforming the swaged portion of the blank into a portion of a ferrule while deforming the unswaged portion of the blank, except for the terminal contact portion, into a coaxial ferrule portion of lesser in- 20 ternal diameter and while forming a shoulder between the ferrule portions resulting in the adjustment of the trimmed edge of th swaged portion of the blank into a plane normal to the ferrule axis.

3. An electrical connector of the deformed sheet type comprising a connector portion and an open ended ferrule portion integral therewith, said ferrule portion including two integral coaxial barrels of different internal diameters, said ferrule having a longitudinal seam with abutting edges, one barrel being adapted to fit around the stripped end of an electrical conductor and the other barrel being adapted to fit over the end of the insulation sheath on the conductor, the thickness of the wall of said barrel of larger diameter being less than the thickness of the wall of said barrell of small diameter in proportion to the differences in diameter. 0 VERNON E. CARLSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

